The present invention relates to a crusher and a movable blade section for the same, more precisely the invention relates to a crusher, which is capable of crushing scrapped members, e.g., resin, rubber, into grains having prescribed size, and a movable blade section for the crusher.
The inventor of the present invention has invented a crusher, which is capable of crushing scrapped resin into grains having a prescribed size for reuse. The crusher has been disclosed in Japanese Patent Kokai Gazette No. 7-39776. Before the inventor invented said crusher, crushers had rotary blades for crushing scrapped members. On the other hand, the crusher, which has been disclosed in said gazette, has a fixed blade section, which has a plurality of shearing blades, and a movable blade section , which has a plurality of shearing blades engaging with the shearing blades of the fixed blade section. The movable blade section is linearly reciprocatively moved to shear or crush the scrapped members into grains.
The crusher disclosed in said gazette is shown in FIG. 13. The crusher shown in FIG. 13 has a rotary blade section 10 and fixed blades 12. Members to be crushed, e.g., scrapped resin, are roughly crushed between the rotary blade section 10 and the fixed blades 12. The rotary blade section 10 is provided in the vicinity of an upper opening section of a body proper 14; a fixed blade section 20a and a movable blade section 20b, which are capable of crushing the members, which have been roughly crushed between the rotary blade section 10 and the fixed blades 12, into grains, are provided in a lower part of the body proper 14. The inner space of the body proper 14 is gradually made narrower toward the blade sections 20a and 20b, so that the members, which have been roughly crushed between the rotary blade section 10 and the fixed blades 12, can be securely introduced onto engaging portions of the blades of the fixed blade section 20a and the movable blade section 20b.
The fixed blade section 20a and the movable blade section 20b are formed into block shapes. They are diagonally provided to introduce the members roughly crushed toward the engaging section thereof. The members roughly crushed are further crushed into grains by slidably engaging the movable blade section 20b with a lower face of the fixed blade section 20a. The fixed blade section 20a and the movable blade section 20b are shown in FIG. 14. They shear (crush) the members twice within one stroke of the movable blade section 20b. So the fixed blade section 20a has first blades 22 and second blades 24; the movable blade section 20b has third blades 26 and the fourth blades 28.
The members are firstly sheared between the first blades 22 and the third blades 26; they are secondly sheared between the second blades 24 and the fourth blades 28. The blades 22, 24, 26 and 28 are linearly arranged at the regular intervals as shown. The intervals define grain size of the crushed members, which have been crushed by the fixed blade section 20a and the movable blade section 20b. Inner side faces of projected parts 29 of the first blades 22 act as blade faces; edges of concave sections of the second blade 22 act as blade faces.
FIG. 15A shows the member 30 not crushed; FIG. 15B shows the member 30 which has been firstly sheared between the first blades 22 and the third blades 26. The first shearing is executed between the first blades 22 and the third blades 26 as if they bite the member 30. When the member 30 is firstly sheared, parts corresponding to the third blades 26 are removed from the member 30, so that the member 30 is formed like a comb. Projected sections of the member 30, which have been firstly sheared, are removed by the second shearing, so that the member 30 is formed into a columnar stick.
In the first shearing, the removed parts are formed into grains and discharged by the downward movement of the third blades 26; in the second shearing, the removed parts are also formed into grains and discharged through discharging holes 28a of the fourth blades 28. The discharging holes 28a are opened in lower faces of the movable blade section 20b, and the removed grains are discharged from the opening sections thereof.
With the above described structure, the crusher is capable of crushing (shearing) the members to be crushed into grains with fixed size. In the case of crushing scrapped resin, the resin grains can be reused.
However, the above described crusher has the following disadvantages.
The members to be crushed are roughly crushed by the rotary blade section 10 in the body proper 14, then they fall onto the engaging sections of the fixed blade section 20a and the movable blade section 20b and are further crushed into grains. But some grains stay on the engaging sections, so that they are not crushed by the fixed blade section 20a and the movable blade section 20b. Especially, scrapped resin is apt to stay thereon by static electricity.
In the above described crusher, a motor for rotating the blades of the rotary blade section 10 drives a cam mechanism for reciprocatively moving the movable blade section 20b. In FIG. 13, a cam plate 34 holds the movable blade section 20b. An eccentric roller 38 engages with a window section 36 of the cam plate 34. The eccentric roller 38 is rotated by the motor to reciprocatively move the cam plate 34. By employing such a complex cam mechanism, noise and vibration are generated in the crusher.
In the above described crusher, the fixed blade section 20a and the movable blade section 20b have a plurality of blades, and the blades are arranged with intervals, which are defined according to grain size, so each interval of adjacent blades is 3-4 mm. The blades with said intervals are made by, for example, electrical discharge machining, but it is difficult to make the blades by electrical discharge machining, and the machining cost is high.